A collapsible-type zoom lens barrel is so adapted that a group of lenses for sensing the image of a subject is compactly accommodated within a camera body when an image is not being sensed and is projected from the camera body only when an image is to be sensed.
Cameras have become increasingly compact in recent years and it is now required that the collapsible-type zoom-lens lens barrel have a shorter accommodating length for accommodating the lens group in the camera body when an image is not being sensed. However, the accommodating length of the collapsible-type zoom lens depends upon the thickness of the lens group inside the lens barrel and it cannot be reduced to a length less than that of the thickness of the lens group.
In order to deal with this problem, it has been proposed to reduce the accommodating length of the lens barrel by withdrawing some of a plurality of optical elements to a position away from the optical axis of the remaining optical elements, and accommodating at least some of the optical elements, other than those withdrawn, in the space on the optical axis where the withdrawn optical elements were located (see the specification of Japanese Patent Application Laid-Open No. 2003-315861).
Further, in addition to the need for more compact cameras, an improvement in image quality also is required. Accordingly, a lens barrel equipped with an image blurring correction mechanism for optically correcting for camera shake as caused by an unsteady hand has been proposed (see the specification of Japanese Patent No. 3513329 and the specification of Japanese Patent Application Laid-Open No. 2004-101721).
With the method described in Japanese Patent Application Laid-Open No. 2003-315861, however, a withdrawing member such as a torsion bar, which is unnecessary when an image is sensed, is required as a component needed to withdraw some of the optical elements from the optical axis. This leads to an increase in cost.